Bolster for four-wheel commercial and farm trailers



June 14, 1949. o. A. KLOCKAU BOLSTER FOR FOUR-WHEEL COMMERCIAL AND FARM TRAILERS 2 Sheets-Sheet 1 Filed Jan. 24, 1947 INVENTOR. (0% a W W Z'fQZlEa/HWMAZZ.

1 5 ARarne June 14, 1949. o. A. KLOCKAU BOLSTER FOR FOUR-WHEEL COMMERCIAL AND FARM TRAILERS Filed Jan. 24, 1947 Z'SheetS-Sheet 2 mmvrozc (0% 60.1fm. "WWW/M.

his An'ornev Patented June 14, 1949 BoLs'rER Pontoon-WHEEL COMMERCIAL AND-FARM TRAILERS Otto; A. Klockau, Roclg island, Ill. -App1ication January 24, 1947,.Serial -N0. 524,183

3 Claims.

My inventionihas referenceto a spring balancedbolster for four. wheel commercial and .iarm

trailers, and has for its purpose .to equalize the shifting weight :of the load, and absorb any shock producing movement so as to prevent the same from-contacting the usual-posts of the running gear, which might cause injury or breakage thereto.

One of the objects of ,the invention is to provide a unitary bolster support of a resilient character by means of which the load will be well balanced against lateral movement. This includes a double bolster formation, with a false or floating bolster, and springs interposed between the bolster plates of a character to help carry the load. Special features are made use of in carrying out this part of the invention.

Another purpose of the invention is to guard the trailer apparatus from lengthwise movement of the load, such as might result in breakage of the vehicle posts or other part of the equipment. When the trailer and its load come to a stop there is a tendency of the load to lunge forwardly, with a considerable strain on the posts, and when the vehicle is started there is a similar tendency, but in the opposite direction. A similar tendency is encountered when the vehicle is moving upwardly or downwardly on a grade. Means are provided in the present invention for compensating for this action, and preventing the same from being directed against the trailer posts or stakes.

The above named, and other features and advantages of the invention will more fully appear from the following specification, taken in connection with the accompanying drawing, in which,

Fig. 1 is a side view of a vehicle bed, with parts in section.

Fig. 2 shows one of the bolster units in side view.

Fig. 3 is a lower plan view of the upper bolster plate, detached.

Fig. 4 is a plan view of the lower bolster plate, detached.

Fig. 5 is an end view of the bolster unit.

Fig. 6 is a cross-section on the line 6-6 of Fig. 2 with parts broken away.

Referring first to Fig. 2, the number 8 indicates one of the axles of a four-wheel trailer, upon which is supported a bolster plate 9, with recesses Ill in its ends to accommodate a pair of posts ll of usual construction, secured at the ends of the axle '8, as by bolts l-2. Above the plate 8 is supported a false bolster plate 13, of inverted channel-plate formation, by means of heavy coiled springs l4, held in spaced relation with each other near .the, ends of the bolster plates by. means of circularrdetents l5, fitting into the lower coils. of

qthe;springs. :The lower face of the plate 13 .is

fitted with similar detents sand IT, in register with -the-detents l5, and engaged by the upper ...ends of the springs. The detents I! are of greater .lensth than .theothers, and are adapted for con- .tact. with the detents I5 just below them,,to limit the closing action of the springs. The. posts ll .arealsopreferably formed of channel-platematerial, similarly to the plate l3.

The plate I3 is provided with recesses 20 in its ends, to accommodate movement of the plate vertically of the posts, with a little clearance between the posts and side edges of the recesses to permit independent movement of the plates. The posts are also fitted with lugs I9 midway their heights, which serve as stops and limit the upward movement of the plate l3, preventing any possible escape of the springs I 4 from between the plates. Each of said posts has a base 2| which fits snugly into the opening in the plate 9, and keeps such posts from turning.

The operation :of the device will be obvious. The variation in the weight on the ends of the bolsters will be counterbalanced by the springs l4, and the load accommodated to changes in the surface of the road. It will have a floating movement with relation to the wagon gear parts of the trailer. It will be understood that the front end of the trailer is fitted with means for connection with a tractor or other traction vehicle, but not shown in the drawing.

In Fig. 1 is shown a pair of axles 8, united by a reach 23, of tubular form, with a telescopic section 24, not new in the present device, and fixed to the reach 23 towards each end thereof are clamping collars 25, secured by ears 26 connected with a bolt 21, and similar ears 28 held together by pins 29, upon which the held the inner ends of chains 30, the other ends of which are fitted with threaded pins 3 I, inserted through openings 32 in the inner flanges l3a of the plates l3. The pins are provided with nuts on the inner and outer faces of the flanges l3a, as indicated at 33. and can be adjusted to increase or lessen the tension of the chains. Each of the chains is held reasonably taut, but has a limited amount of stretch, or yield to permit a rocking movement outwardly of the plate l3 to which it is attached. The strain which would otherwise be received by the post II is thereby applied to the chain, with the limited rocking movement of the upper bolster plate further controlled by the springs M on which it rests. The chains are 3 oppositely disposed, so that one of them takes care of a lunging movement of the load toward the front, and the other one a similar movement to the rear.

The rocking movement of the springs l4, taken in connection with the yieldable restricting action of the chains 30 adds to the floating action already referred to, and makes the balancing support of the load complete.

Changes can be made in the manner of construction and operation of the invention without departing from the spirit of the invention, as set forth and claimed herein.

What I claim, and desire to secure, is-

1. In a device of the class described, the combination with a vehicle reach and axle attached thereto, and posts supported at the ends of said axle, of a two-part bolster mounted on said axle including a lower plate and upper plate having a vertically sliding connection with said posts, interposed springs, and a chain connection be tween said upper plate and said reach, permitting a limited rocking movement to said upper plate, independently of the posts.

2. In a device of the class described the combination with a vehicle frame, including a pair of axles and connecting parts, and posts supported from the ends of said axles, of a twopart bolster on each of said axles, including lower plates on said axles and upper plates spaced 4 above the same, having vertical play on said posts, and interposed springs, and chain connections between said upper plates and said frame parts, permitted limited rocking movements outwardly of said upper plates.

3. In a device of the class described, the combination with a vehicle reach and axle attached thereto, and posts fixed on the ends of the axle and provided with stops midway their ends, a two-part bolster mounted on said axle, including a removable lower plate, and an upper plate spaced therefrom having vertical play on said post, and limited in its upward movement by said stops, and a chain connection between said upper plate and said reach, provided at one of its ends with means for adjustment of the length thereof, and compression springs interposed between said plates.

OTTO A. KLOCKAU.

REFERENCES CITED The following referen'ces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 873,221 Edwards Dec. 10, 1907 1,398,810 Story Nov. 29, 1921 1,610,037 Canevaro Dec. '7, 1926 

